Rates increase at weekly Treasury bill auction

WASHINGTON (AP) - Interest rates on short-term Treasury bills rose in Monday's auction to the highest levels since early March.

The Treasury Department auctioned $22 billion in three-month bills at a discount rate of 1.610 percent, up from 1.420 percent last week. Another $21 billion in six-month bills was auctioned at a discount rate of 1.740 percent, up from 1.700 percent last week.

The three-month rate was the highest since these bills averaged 1.790 percent on March 3. The six-month rate was the highest since 1.810 percent, also on March 3.

The discount rates reflect that the bills sell for less than face value. For a $10,000 bill, the three-month price was $9,959.30 while a six-month bill sold for $9,912.03.

Separately, the Federal Reserve said Monday that the average yield for one-year Treasury bills, a popular index for making changes in adjustable rate mortgages, rose to 1.93 percent last week from 1.88 percent the previous week.